METHOD OF MANUFACTURING SEMI-CLOSED PROFILES Russian patent published in 1994 - IPC

FIELD: plastic working of metals. SUBSTANCE: method involves forming central portion of billet to obtain tray-shaped intermediate profile; forming end portions and providing final shaping of profile by tucking out double-strip members and inclined walls conjugated with profile and having arced flanges in several steps; making double strips during terminating steps and reducing them by applying vertical forces to both sides of strips; forming end portions of flanges in succession from periphery to center along constant-radius arcs followed by reduction with transverse forces applied to outer portions of above mentioned portions; during final forming, tucking out walls for an angle equal to predetermined angle between double strip members and inclined walls and simultaneously tucking out arced flange end portions by forces applied to outer part of above mentioned portions perpendicular to them; tucking out inclined walls with arced flanges by horizontal forces initially applied to double-strip member and inclined wall joints and then to outer part of arced flanges to obtain double strips; effectuating reduction of strips; performing upsetting of arced flanges, upon forming double strips, by applying vertical distributed forces to outlines of arced flanges to provide profile height of predetermined value. EFFECT: increased quality of profiles by preventing discontinuity of covering and high-quality forming of arced flanges. 2 cl, 2 dwg, 1 tbl